Method and mechanism for separating intermixed divided materials



K. DAVIS Dec. 30, 1930.

METHOD AND MECHANISM FOR SEPARATUJG INTERMIXED DIVIDED MATERIALS Original Filed May 28, 1924 6 Sheets-Sheet Dec. 30, 1930. K. DAVIS 1,786,740

METHOD AND MECHANISM FOR SEPARATING INTERMIXED DXVIDED MATERIALS INVENTOR ATroRNEY Dec. 30, 1930. DAVIS 1,786,740

METHOD AND MECHANISM FOR SEPARATING INTERMIXED DIVIDED MATERIALS- Original Filed May 28, 1924 6 Sheets-Sheet 3 07 lz I57 /23 I WI! 124 /82 I85 INVENTOR Dec. 39, 1930.

K. DAIVIS METHOD AND MECHANISM FOR SEPARATING INTERMIXED DIVIDED MATERIALS Original Filed May 2s,

MQQZM ATTORNEY Dec. 30, 1930 DAv|5 1,786,740

.METHOD AND MECHANISM FOR SEPARATING INTERMIXED DIVIDED MATERiALs Original Filed May 28, 1924 6 Sheets-Sheet 5 IN VENTOR ATTO EY Dec 30, 1930. K. DAVIS 1,786,740

METHOD AND MECHANISM FOR SEPARATING INTERMIXED DIVIDED MATERIALS Original Filed May 28, 1924 6 Sheets-$heet 6 q INVE'NTOR v ATTORNEY Patented Dec. 30, 1930 UNITED STATES PATENT OFFICE KENNETH DAVIS, OF EBENSBURG PENNSYLVANIA, ASSIGNOR, BY MESNE ASSIGN- MEN'IS, 'I'O PEALE-DAVIS COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION or DELAWARE 1 METHOD AND MECHANISM FOR SEJPARATING INTERMIXED DIVIDED MATERIALS Application filed May 28, 1924,- Serial No. 716,322. Renewed September 24, 1929.

The invention relates to a novel and improved process and mechanism for separatlng lntermixed divided materials by the action of air and through their differences in specific gravity.

Objects and advantages of the invention Wlll be set forth in part hereinafter and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended-claims.

The invention consists in the novel parts, constructions, arrangements, combinations and improvements herein shown and described.

The accompanying drawings, referred to herein and constituting a part hereof, illustrate one embodiment of the invention, and together with the description, serve to explain the principles of the invention.

Of the drawings Fig. 1 is a central, vertical, longitudinal Eection, taken substantially on line 1-1 of ig. 2 is a full horizontal section, taken substantially on line 22 of Fig. 1;

Fig. 3 is a full transverse vertical section, taken substantially on line 33 of Fig. 1;

Fig. 4 is a full horizontal section, taken substantially on line 44 of Fig. 1;

Fig. 5 is a transverse, vertical section, taken on line 5-5 of Fig. 1;

Fig. 6 is a diagrammatic plan, showing zones of different air perviousness in the bed or table;

Fig. 7 is a transverse vertical section of the table, but showing a different form of separating partitions;

Fig; 8 is a fragmentary plan showing the separating mechanism and delivery devices adapted to separate the clean coal according to sizes; and

Fig. 9 is a vertical section on line 9-9 of Fig. 8.

The invention is directed to effecting rapid, economical and especially very eflicient and complete separation of intermixed divided materials by conjoint action upon a continuously maintained bed of the intermixed materials of a variably-regulated, or successively graduated, upward air blast or current and of cooperating movements and stoppings of the bed. Thereby flotation of the lighter intermixed material or materials in the bed is effected, with upward movement or sustention thereof, while the heavier intermixed material or materials is caused to subside or sink through the bed, with a resultant stratification and thereby separation of the materials, and a progression of the separated materials in the bed along difierent paths to separate places of delivery or discharge.

The term intermixed divided materials comprises broken .materials, or materials otherwise in relatively small pieces or particles, and intermixed together. An example of such materials is coal, bony and rock as it comes out of the mine.

The invention is further directed to rapid, economical and very efficient separation, in the manner described, of intermixed divided materials wherein the pieces of materials vary relatively very greatly in size,-while the materials themselves vary relatively but very little in specific gravity. This naturally makes the rapid and thorough separation of the intermixed materials an unusually difficult task.

An example of such intermixed materials is the mixture of coal and rock, or coal, bone and rock, already referred to. It has been usual heretofore in mechanically cleaning coal to size the intermixedmaterials very minutely preparatory to separation thereof. That is, there are usually many repeated screenings of the material, so that it is ultimately separated into a large number of parts according to the size of the pieces; the graduations, especially in the smaller sizes, being frequently within a sixteenth or a thirty-second of an inch.

As a consequence the coal and rock in each of these screened sizes of the material must be independently separated; For instance, should there be .ten screened sizes, there would of necessity be nine screening or sizing operations and ten separating operations. By my invention, not only are all the troublesome, expensive, tedious, and time-consuming sizing operations,.and the necessary and expensive machinery, obviated, but all the subsequent separations 'save one are avoided, as by my invention the unsized intermixed materials are separated as they come.

l In practice, by my invention, by way of one practical'example, rapid and thorough separation of all sizes from two and onehalf inches down is effected at one operation and without any preparatory -sizing or screening.

The present invention is also directed to a novel process and mechanism for eifectlng a substantial grading or classification of the coal or lighter materials according to size concurrently with the purification or separation thereof. By this feature of my invention different sizes of clean coal are delivered from different portions of the bed, the coal being discharged in a stream or streams which are gradated in size substantially across the general direction of their flow.

A similar or analogous size-classifying action is described and shown in my earlier copendingapplication ber. No. 553,250, filed April 15, 1922, but is not claimed therein.

- The present preferred exemplary embodiment of my invention comprises roadly a flat air-pervious table, proportioned through out for the best results and inclined from the rear upwardly to the forward end, the table starting from a relatively narrow rear portion and broadening outwardly forwardly to a median point in its length, and from that broadest part, gradually narrowing to the front end, which is preferably somewhat narrower than the rear end.

On the top of the air-pervious table are a series of vertically and parallelly disposed separating partitions, arranged preferably in sets or in pairs considered transversely of the table at either side of its longitudinal central line. These pairs of separating partitions mutually converge inwardly and forwardly .along the table, and terminate so as to leave a longitudinally-disposed passage along the center of the table through which the heavier material, stratified and resting upon the table is progressed unimpededly toward the discharge place therefor at the front of the table. Preferably the separating partitions also begin at the back edges of the table and are substantially parallel to the front side edges of l the table.

Preferably also, the inner ends of the successive pairs of separating partitions, cons dered forwardly of the table, terminate a little farther apart so that the central, longitudinally-disposed channel gradually broadens forwardly. This serves to adequately accommodate all the gradually increasing vol-' ume'of rock or other heavier material, as it comes inwardly from the successive pairs of separating partitions, and slides along the surface of the table forwardly toward the place of discharge.

The separating partitions also terminate at some distance from the -forward end of the table, leaving the forward end thereof unobstructed completely across, so that the rock or heavy material may spread out and accumulate near the discharge end and functions in a manner fully described later herein. The discharge of the rock from the table is regulated by a pressure balancing system also later fully described.

The air perviosity of the table is regulated to decrease both forwardly andoutwardly along the table from a maximum'at or near the rear end of the table, at the point where the intermixed materials are fed onto the table. The decrease is very gradual and is practically effected by a series of zones of decreasing perviosity. Y

Thereby the main work of Stratification and separation is quickly accom lished at and near the place of feeding the intermixed materials onto the table, while the work of separation is continued and extended both outwardly and forwardly along the table. This continued and protracted, or repeated, separating action is especially effective in viewof the great variation in size of the intermixed pieces of material in conjunction with the relative small difference in the specific gravity of the materials.

The intermixed materials are fed on to the bed at the rear end in such variable and regulated quantity as to maintain always a substantially uniform bed of the materials undergoing separation upon the table.

It will be understood that the foregoing general description and the following detailed description are exemplary and explanatory of the invention, but are not restrictive thereof.

Referring now in detail to the accompanying drawings, illustrating by way of example one embodiment of the invention, a table 1 of air-pervious material is provided, upon which the bed of materials rests during the process of separation. This table will be described in detail later, in connection with the graduated airperviousness of the different parts thereof to facilitate and complete the gradual separating process. The table 1 is preferably flat and inclined upwardly and forwardly of the machine, that is, from the right toward the left in Fig. 1.

The air-pervious table 1 is preferably relatively narrow at the rear end, where the intermixed materials are fed thereonto, and widens outwardly and forwardly to a median point in the length thereof, and preferably somewhat short of the middle of the length of the table. From this widest art, the table narrows inwardly and forwar ly to the front and discharge end, and this end is preferably somewhat narrower than the rear end thereof.

The table is supported upon a suitable frame, comprising transverse end pieces 2 and 3, and side reaches 4 and 5, which are angled to conform to the previously-described exterior shape or contour of the table. There port the table lunderneath at various points along its len h. 7 The table 1 in addition to being air-per' through a short path, this movement at the forward end thereof terminating in a relatively sharp impact. In the embodied form of means for providing for the combined air action and mechanical movement described, there is an air chamber beneath the table and also mountings and mechanism between the table and chamber for effecting the 'desired movement. The chamber beneath the table (Figs. 1 and 3) is contracted or decreased downwardly and inwardly at the sides. The frame carrying the air-pervious table 1, accordingly, has at the sides thereof, a series of inwardly and downwardly inclined supports 8 and 9, which at their lower ends are fixed to and supported by side reaches 10 and 11 of a rectangular frame (Figs. 1, 3 and 4).

The ends of the table 1 are carried by supports 12 and 13, which in turn are fixed to and supported by the end reaches 14 and 15 of the rectangular frame. This framework is surrounded by -an envelope of canvas or other flexible and impervious material frame and to the rectangular frame in airtight connection. r

F or the purpose of permitting the reciprocatory movement described (Figs. 1, 3 and 4), the rectangular frame 10, 11, 13, 14 ispivotally supported at points 20 and 21 upon a pair of arms 22 and 23, which arms, respectively, have pivotal mountings 24 and 25' at their bottom ends upon the side reach 26 of the rectangular top frame of the stationary air chamber. A like mounting is provided on the other side, wherein a pair of arms 30 and 31 are pivoted at their top ends 32 and 33 to the side reach 11 of the bottom frame of the table structure. At their bottom ends these arms are pivoted, respectively, at 37 and 38 to the other top side reach 39 of the frame of the stationary I air chamber. The table thus has a recipro- 55 catory and very slightly arcuate motion, there being a slight rise thereof during the forward movement, and a slight fall during the return movement.

The air chamber (Figs. 1. 3 and 4) so far as regards many features of the invention. may be of any desired form. As embodied. however. it comprises substantially vertical sidewalls 46 and 47. and a front wall 48. and a rear wall 49. The bottom 50 thereof is rearwardly and downwardly inclined, and

are provided also cross-supports 6, which supvious. is reciprocated longitudinally of itself- 16, which is fixed to the table supporting at the bottom and rear thereof this chamber *opens into an air duct 51, through which the air under pressure is suppliedfrom any suitable device, such as a fan or any other suitable source of air pressure.

In accordance with one feature of the invention, the inclination of the table 1 may be varied (Figs. 1, 3 and 4) andfor this purpose the air chamber at its rear end, and at either side, is carried upon pivotal supports 58 and 59, which are mounted, respectively, upon supporting pillars 60 and 61. Near the forward end thereof, the table has, at either side, ball and socket supports 63 and 64, upon screw posts 64 and 65, which are carried respectively upon supporting pillars 66 and 67. By turning the screw posts 64 and 65, or nuts, mounted thereon, in either direction, the air chamber and table may be rocked about the pivotal bearings-58 and 59 to vary the inclination of the table. The canvas or other flexible and air impervious envelope 16 is carried downwardly and connected air tight to the top frame of the stationary air chamber, as shown at 68 (Figs. 1 and 3).' i

In the embodied form of means (Figs. 1, 2 and 4) for imparting the longitudinal reoiprocation and the-terminal impact to the table, there is provided at the rear end of the table structure a cam roller 7 8, ournaled "in arms 79 and 80, fixed to and extending outwardly from the additional cross reach 14' of the table frame. Cooperating with the cam roller 78 is a cam 82, fixed on a shaft 83, which shaft is journaledat 84 and 85 upon longitudinally-disposed extensions 86 and 87 of the side members 26 and 39 of the top frame of the air chamber. These members are connected together by a cross frame 3 member 88.. y 7

Fixed on the shaft 83 is a pulley 89, overs which runs a belt 90, which also runs over' a small pulley 91', fixed on a shaft 92. On

this shaft there is also fixed a large belt pulley 93. A belt 94 runs over this pulley and over a small pulley 95, on the shaft of a motor 96. This mechanism is carried upon a base 97, carried by hangers 98 from and 116,'at either side,'on the under side of the table frame,'and'a pair of stops 113 and 114 pro ecting upwardly likewise -at either'side, from the top side of the top frame I of the air chamber.

It will thus be seen that the bed, under the impulsion of the cam (see Fig. 1) has a relatively quick upward and forward movement terminating in a sharp impact, due to the action of the springs 111 and 112, and a some what slower downward return movement. The entire movement in practice, however, is usually quite rapid.

Means are provided upon the upper surface of the air pervious table 1 for effecting a gradual separation of the particles of the intermixed materials, whereby the materials are subjected to successive separating actions. That is, a large proportion of the separation is effected very soon after the de posit of the intermixed materials upon the table, but where the pieces or'particles of the intermixed materials vary greatly in size, and the materials themselves vary relatively slightly in specific gravity, there is still an intermixed residual, which has not been separated and stratified 1n said early stages of .the progress of the materials along and through the bed. This residual is subjected to repeated separating actions, and in each such action an additional part of the further separation is effected. Thus, through these repeated separating actions, all the intermixed materials are finally completely and efficiently separated.

As embodied (Figs. 1, 2, 3 and 7), a plurality of upwardly-projecting and preferably perpendicularly positioned, separating partitions 120 are carried upon the upper face of the table 1. These partitions begin at the rear end and the rear side edges of the table,

and extend longitudinally and inwardly of the table toward the central part thereof. They terminate short of the central axis of the table, to provide a longitudinal, unobstructed channel or passageway from the rear to the front of the table for the rock or other heavier, separated material in its travel forwardly along the table to its place of discharge at the front end thereof.

. The separating partitions are arranged in two groups or series at either side of the table, and are preferably in pairs. The successive pairs, or members of the groups, at either side, have their inner ends more and more widely separated from the rear toward the forward end of the table. Thereby the central, longitudinally-disposed, unobstructed channel-way for the heavier material in creases in width forwardly along the table, to provide additional room for the additional heavier-material which is fed in from each successive pair of separating partitions. Preferably, also, the central unobstructed channel-way increases relatively more in width from approximately themiddle part ofthe tablettoward the front end thereof, as best appears in Fig. 2.

There is also preferably provided an unobstructed space entirely, across the narrow forward end of the table (Fig. 2) wherein all the accumulated rock or other heavier material can accumulate preparatory to being discharged. This space is provided by all the separating partitions 120, terminating short of the forward end except the outside pair of separating partitions 121 and 122. These latter preferably join onto the device for controlling the discharge of the heavier material, as will be later fully described. The table is preferably'provided at either side with a relatively narrow, fiat ledge or shelf 123 and 124 just outside the outside separating partitions, respectively, these ledges being impervious to air. The table has a rear upwardly projecting retaining wall 125, and like walls 126 and 127 along the rear portionsof the side reaches of the table, although these latter may be dispensed with, or may extend foronly a desired portion along these rear, widening side edges of the table.

Means are provided (Fig. 1) for feeding on the intermixed divided materials at a rate just equal to the capacity of the table, so as to maintain a substantially uniform bed of the materials upon the table undergoing stratification and separation. As embodied, a hopper 132 is provided with a variable and regulable feed mechanism at the bottom thereof, and discharges through a chute 133 upon the rear central part of .the table 1. This variable and regulable feeding means may be of any suitable or convenient form and is shown herewith as a variable-speed conveyor belt 134, horizontally disposed at the bottom part of the hopper, to feed into the chute. The variable feed drive therefor (not shown) may be of any known or suitable form.

There is also preferably provided a dust collecting mechanism (Fig. 1), and as shown this comprises a top or shell 135, disposed above the table 1, and having downwardly disposed sides and ends 136.- An envelope of canvas or other impervious and flexible material 137, makes air tight connection between the table 1 and the dust collector,

whereby the table may be reciprocated, the dust collector being stationary. The dust is carried off through a channel 138 to a suitable dust collector, which may be of the general form shown in my copeuding patent application, Ser. No. 724.784, filed July 8, 1924.

Means are provided by the invention for controlling the discharge of the heavier material from the table (Figs. 1, 2, 3 and and as embodied, this means operates by regulable pressure of the accumulated separated heavier material, and at the same time the airpressure is controlled to drive back any particles of the lighter material to prevent their being discharged with the heavier material.

As embodied, the table at its forward end terminates in a passageway 148, through which the rock or other heavier material is discharged from the table, this passageway preferably being air-pervious at its top and walls and the top are surrounded by an air chamber having side walls 156, 157 and a top 158, and a front wall 159. This chamber has air-conveying openings 160 and'161 communicating into the general 'air chamber for the table.

The outer end of the discharge passage is closed by a door or gate 170, which is pivotally supported on a rod 171, supportedin standards 172, projecting upwardly from the casing about the passageway. Means are provided for placing variable ressure regu lation upon the door or gate 1 O, and as embodied, a pin 174 projects from the gate, and upon this are placed weights 175. Preferably the forward ends of the outside se arating' partitions 121 and 122 are forwar ly and upwardly inclined, and join the inner ends of the passageway 148 at either side, and at this point are of the same height as the passageway.

and 4) for the rock and coal or other sepa- Suitable discharging means (Figs. 1, 2

rated heavier and lighter materialsare provided. As embodied, a chute 180 receives the heavier material from the passageway 148 and delivers it to a conveyor belt 181. The coal or other lighter material, is discharged into chutes 182 and 183, disposed along the forward, inwardly-converging edges of the table, and being forwardly and downwardly inclined, and discharging onto a conveyor belt 184.

Means are preferably provlded for graduating the force or intensity of the air action'along different parts of the table and also preferably throughout the table. The present preferred arrangement thereof, especially for certain kinds of commercial coal with its intermixed rock and bone is shown in Fig. 6. In this figure, the degrees of'air perviousness of the table are indicated decreasingly by the small italic letters; that is, small a represents the greatest degree of air perviousness; 1) represents the next deg fee of air perviousness, and so on. The tzfble is preferabl arranged in zones, which represents a su ciently accurate practical approximation to a un form graduation throughout the table.-

In Fig. 6, the greatest degree of perviosity is shown by (rat the rear end of the table where the'intermixed materials are fed onto the bed. The table arranged in zones ofdecreasing -air perviousness, longitudinally and forwardly, the last zone at the center of the table being indicated by 6, with zones of lesser air perviousness f at either side.

Considered outwardly from the central axis of the table toward the side edges, the perviousness of the table decreases outwardly as well as forwardly, and terminates near the broadest part of the table in two zones or areas of least perviosity g. To insure uni form air action, as desired, adjustable baflie plates 188 and 189 are shown in the stationary air chamber, having external adjusting handles 188 and 189, and it will be quite obvious that similar baflie plates could be arranged on the table'frame just beneath the table 1 as may be found desirable or convenient.

In Fig. 1 and Fig. 3, the separating partitions are shown of uniform height with rethe side edges of the table.

While the rock or heavy material discharged is preferably operated with an air impervious bottom, means are provided whereby the bottom maybe rendered air Egrvious. As embodied (Figs. 1 and 5) the ttom 190, is of air pervious material, and v a slide 191, of impervious material, such as a board, is mounted to slide therebeneath, and can be withdrawn, thereby rendering the bottom of the passage air-pervious. Preferably also, there is a gate or baffle 192, which may be used in the position of Fig.1, as a baflie to direct the air upwardly, or it may be swung in the clock-wise direction in Fig. -1 and act as a valve to regulate the intensity of the aircurrent or air pressure into the sides and top of the passage 14.8.

The manner of operation of the mechanism is substantially as follows: The'machine may be'considered as in operation with a bed of material covering it, and

the rock sinking by gravity and resting upon the table 1, while the pieces of coal are floated or upwardly impelled by the air current. The

cles, that is, to move them out of mutual con-- tact; so that the downward gravitation or settlement of the rock and the sustention or air current acts also to separate all the partiso rapidly, and the further action of the mechanism is to subject these still intermixed por-,

tions to repeated separating actions until final and complete separation is effected.

The rock which has settled and rested upon the rear central part of the'table, due to its inertia and frictional engagement with the table, is slid'forwardly by the reciprocatory movement along the table toward the place of discharge at the forward end thereof. As the still intermixed parts of the materials in the bed are progressed along the table they are successively subjected to a separating action at each successive separating partition.

Behind each of these partitions the process is repeated of separating the particles or pieces out of contact with each other. The particles of rock settle onto the table behind the partition, and the particles of coal are floated over the partition and progress forwardly and outwardly due to the motion of the table. The rock, however, which has settled upon the table behind the separating partition, due to its inertia and frictional engagement with the table, is progressed forwardly, and, due to the position of the separating partition, also inwardly into the stream .of rock in contact with and flowing along the table forwardly to the place of discharge at the forward end of the table.

Thus, the size are sub ected at each separating partition to a decreasing upward air current force, and settle onto the bed, and thus finally the finest dust of the rock is.c aught by a separating partition and directed along it and forwarded along the central part of the table. During the whole process the-air has either sustained or impelled and floated the particles or pieces of coal upwardly, and these finally form a substantially pure layer at the top layer or stratum at the top of the bed.-

The air pressure may be nicely regulated so that at the edges ofthe table the bed of coal is just practically sustained or balanced on the air. a

Due to the motion of the table, all of the materials are impelled forwardly, and the forward end of the table being normally closed, and due to the contraction in area forwardly, the upper stratumof separated coal passes out over the side edges of the table, and is discharged into the chute designed to receive it. By reason of the gradually widening central channel and the unobstructed space at the forward part of the table, the rock has free and ready access toward the forward end of the table, and at the same time tends crowd or direct the for-'- articles of rock of less and less upon the gate 170. As the quantity of rock increases at the forward end of the table, the gate 170, due to the increased pressure, will be swung open and the rock will be forced forwardly and pass out through the passageway 148, and be discharged. As the pressure gradually decreases the gate 170 will again close. I

The air blown normally in through the sides and top of the passageway 148 must escape inwardly and upwardly into the front end of the table, and thus will blow back any particles of coal at the top of the rock on to the'top of the stratum of coal. As the pressure of the rock increases and the door 170 is opened, this air current, thereby increases and prevents any discharge of the coal during the discharge of the rock. Thus, the mechanism is designed to effect complete separation of the coal and rock through the wide variation in sizes, thereby avoiding the troublesome and expensive sizing and the corresponding equipment therefor, and the subsequent and consequent necessity for a plurality of separating mechanisms, whereas I the resent invention requires but one.

same are provided (Figs. 8 and 9) by the invention for separating and delivering the clean coal in different sizes, and as embodied, in the modification shown in Figs. 8 and 9, the chutes 182 and 183 are divided into sections longitudinally, each section having means for delivering separately the clean coal delivered thereto. Chute 182 is shown having a discharge opening 200 in its bottom, located well toward the forward part thereof. A discharge chute or spout 201 receives the coal dropping through opening 200 and discharges it onto a conveyor belt 203. A

partition 202 across chute 182 may also be off the clean coal-at a plurality of points along the table edges, a corresponding separation of the c lean coal according to sizes is effected. The smaller ieces of coal are delivered over the side e ges of the table nearest the rear end of the table, the pieces of coal gradually increasing in size forwardly along the side edges toward the front of the table, the largest pieces being delivered at the front part of the side edges. The separated delivery onto different conveyors for different areas or lengths along the side edges delivers the clean coal in different sizes, the gradation depending in part on the number of separate deliveries. There is thus provided a process of sizing or separating the clean coal in connection with the delivery thereof from the separating operation and without any separate operation or mechanism.

The invention in its broader aspects is not limited to the exact mechanisms and constructions herein shown and described, nor to the precise manner of carrying out the process; as departures may be made ,therefrom within the scope of the accompanying claims without departing from the principles of the invention or sacrificing its chief advantages.

What I claim is 1. A mechanism for separating intermixed divided materials including in combination an air pervious table for a bed of the materials and material separating means comprising separating partitions in sets at either side of the table and'converging inwardly and forwardly of the table but terminating short of the center thereof, the ends of the successive partitions being farther apart forwardly along the table to provide a forwardly widening passage for the heavier separated material along the table.

2. A mechanism for separating intermixed divided materials including incombination an air pervious table for a bed of the materials and material separating means comprising separating partitions in sets at eitherside of the table and converging inwardly and forwardly of the table but terminating short of the center thereof, the ends of the successive partitions being farther apart forwardly along the table to provide a forwardly widen ing passage for the heavier separated material along the table, meansfor forcing air through the table and means for varying the intensity of the air currents in different parts of the table.

3. A mechanism for separating intermixed divided materials including in combinaton an air pervious table for a bed of the materials and material separating means comprising separating partitions in sets at either side of the table and converging inwardly and forwardly of the table but terminating short of the center thereof, the ends of the successive partitions being farther apart. forwardly along the table to provide a forwardly widening passage for the heavier separated mate,- rial along the table, means for forcing air through the table and for decreasing the intensity of the the table. I

4. A mechanism for separating intermixed air currentsforwardly along divided materials including in combination an air pervious table for a bed of the materials and material saparating means comprising separating partitions in sets at either side of the table and converging inwardly and forwardly of the table but terminating short of the center thereof, the ends of the successive partitions being farther apart forwardly along the table to provide a forwardly widening passage for the heavier separated material along the table, means for forcing air through the table and for decreasing the intensity of the air currents outwardly from the central part of the table.

5. A mechanism for separating intermixed divided materialsincluding in combination an air pervious table for a bed of the materials and material separating means comprising separating partitions in sets at either side of the table and converging inwardly and forwardly of the table but terminating short of the center thereof, the ends of the successive partitions being farther apart forwardly along the table to provide a forwardly widening passage for the heavier separated material along the table, and means including air current controlling devices for'regulating the discharge of the heavier material from the front of the table.

6. A mechanism for separating intermixed divided materials including in combination an air pervious table for a bed ofthe materials and material separating means comprising separating partitions in sets at either side of the table and converging inwardly and forwardly of the table but terminating short of the center thereof, the ends of the successive partitions being farther apartforwardly along the table to provide a forwardly widening passage for the heavier separated material along the table, and means responsive to the pressure of accumulated separated material and means acting to direct air currents backwardly for regulating the discharge of the heavier material from the front of the table. I

7. A mechanism for separating intermixed divided materials including in combmation an air pervious table for a bed of the materials and material separating means comprising separating, partitions in sets at either side of the table and converging inwardly and forwardly of the table but terminating short of the center thereof, the ends of the successive partitions being farther apart forward- 1y along the table to provide a forwardly wide ening passage for the heavier separated material along the table, said separating partitions terminating short of the forward end of the table thereby leaving an fopen space for the expansion of the heavier ,;separated material as it emerges from said passage.

8. A mechanism for separating intermixed.

divided materialsincluding in combination an air pervious table for a bed of the materials and material separating means comprising separating partitions in sets at either side of the table and converging inwardly and forwardlyof the table but terminating short of the center thereof, the ends of the successive partitions being farther apart forwardly along the table to provide a forwardly widening passage for the heavier separated material along the table, said separating partitions terminating short of the forward end of the table thereby leaving an open space for the expansion of the heavier separated material as it emerges from said passage, and means responsive to the pressure of accumulated separated material for regulating the discharge of the heavier material from the front of the table. ;9. A mechanism for separating intermixed dlvided materials including in combination an air pervious table for a bed of the materials and material separating means comprising separating partitions in sets at either side of the table and converging inwardly and forwardly of. the table but terminating short of the center thereof, the ends of the successive partitions being farther apart forwardly along the table to provide a forwardly widening passage for the heavier separated material along the table, means for forcing air through the table, means for varying the intensity of the air currents in different parts of the table, and means for regulably feeding the intermixed materials-to the table to maintain the bed of materials thereon substantially forwardly widening passage for the heavier separated material along the table, means re sponsive to the pressure of accumulated separated material for regulating the discharge of the heavier material from the front of t 6 table, and means for regulably feeding the intermixed materials to the table to maintain the bed of materials thereon substantially uniform.

11. A mechanism for separating intermixed divided materials including in combination an air pervious table for a bed of the materials the air perviosity of the table de-v creasing from the rear to the front, and-material separating means comprising separating partitions in sets at either side of the table and converging inwardly and forwardly of the table but terminating short of the center thereof, the ends of the successive part1t1ons being farther apart forwardly along the table to provide a forwardly widening passage for the heavier separated material along the table,

said separating partitions terminating short table for a bed of the materials and material separating means comprising separating partitions in sets at either side of the table and converging inwardly and forwardly of the table but terminating short of the center thereof, the ends of the successive partitions being farther apart forwardly along the table to provide a forwardly widening passage for the heavier separated material along the table, said separating partitions terminating short of the forward end of the table thereby leaving an, open space for the expansion of the heavier separated material as it emerges from said passage, means for forcing air through the table, means for varying the intensity of the air currents in different parts of the table, and means for regulably feeding the intermixed materials to the table to maintain the bed of materials thereon substantially unlform.

13. A mechanism for separating intermixed divided materials including in combination an air pervious table for a bed of 'the materials and material separating means comprising separating partitions in sets at either side of the table and converging inwardly and forwardly of the table but terminating short of the center thereof, the ends of the successive partitions being farther apart forwardly along thetable to provide a forwardly widening passage for the heavier separated material along the table, said separating partitions terminating short of the forward end of the table thereby leaving an open space for the expansion of the heavier separated material as it emerges from said passage, means responsive to the pressure of accumulated separated material for regulating the discharge of the heavier material from the front of the table, and means for regulably feeding the intermixed mater als to the table to maintain the bed of-materials thereon substantially uniform.

14. A mechanism for separating intermixed divided materials including in com-4 bination an air pervious table for a bed of the materials and material separating means comprising separating partitions in sets at either side of the table and converging inwardly and forwardly of the table but terminating short of the center thereof, the .ends of the successive partitions being farther apart forwardly along the table to provide a forwardly widening passage for the heavier separated material along the table, means for forcing air through the table and means for varying the intensity of the air currents in different parts of the table, and means for longitudinally reciprocating the table.

15. A mechanism for separating intermixed divided materials including in combination an air pervious table for a bed of the materials and material separating means comprising separating partitions in sets at either side of the table and converging inwardly and forwardly of the table but terminating short of the center thereof, the ends of the successive partitions being farther apart forwardly along the table to provide a forwardly widening passage for the heavier separated material along the table, means responsive to the pressure of accumulated separated material for regulating the discharge of the heavier material from the front of the table, and means for longitudinally reciproeating the table.

16. A mechanism for separating intermixed divided materials including in combination an air pervious table for a bed of the materials and material separating means comprising separting partitions in sets at either side of the table and converging inwardly. and forwardly of the table but terminatmg short of the center thereof, the ends of the successive partitions being farther apart forwardly along the table to provide a forwardly widening passage for the heavier separated material along the table, means responsive to the pressure of accumulated separated material for regulating the discharge of the heavier material from the front of the table, means for regulably feeding the intermixed materials to the table to maintain the bed of materials thereon substantially uniform, and means for longitudinally reciprocating the table.

17. A mechanism for separating intermixed divided materials including in combination an upwardly inclined air pervious table for a bed of the materials and material separating means comprising separating partitions in sets at either side of the table and converging inwardly and forwardly of the table but terminating short of the center thereof, the ends of the successive partitions being farther apart forwardly along the table to provide a forwardly widening passage for the heavier separated material along the table,means responsive to the pressure of accumulated separated material for regulating the discharge of the heavier material from the front of the table, means for regulably feeding the intermixed materials to the table to maintain the bed of materials thereon substantially uniform, and means for longitudinally reciprocating the table.

18. A mechanism for separating mtermixed divided materials including in combination an air pervious table for a bed of the materials and material separating means comprising separating partitions in sets at either side of the table and beginning at the rear and side edges of the table and convergmg inwardly and forwardly of the table but terminating short of the center thereof, the

ends of the successive partitions being farther apart forwardly along the table to provide a forwardly widening passage for the heavier separated material along the table.

19. A mechanism for separating inter,- mixed divided materials including in combination an air pervious table for a bed of the materials and material separating means comprising separating partitions in sets at either side of the table and beginning at the rear and side edges of the table and converging inwardly and forwardly of the table but terminating short of the center thereof, the ends of the successive partitions being farther apart forwardly along the table to provide a forwardly widening passage for the heavier separated material along the table, means for forcing air through the table and means for var ing the intensity of the air currents in di erent parts of the table.

20. A mechanism for separating intermixed divided materials including in combination an air pervious table for a bed of the materials and material separating means comprising separatin partitions in sets at either side of the ta le and beginning at the rear and'side edges of the table .and converging inwardly and forwardly of the table but terminating short of the center thereof, the ends of the successive partitions being farther apart forwardly along the table to provide a forwardly widening passage for the heavier separated material along the.

table, and means responsive to the pressure of accumulated separated material for regulating the discharge of the heavier material from the front of the table.

21. A mechanism for separating intermixed divided materials including in combination an air'pervious table for a bed of the materials and material separating means comprising separating partitions in sets at either side of the table and beginning at the rear and side edges of the table and converging inwardly and forwardly of the table but terminating short of the center thereof, the ends of the successive partitions being farther apart forwardly along the table to provide, a forwardly widening passage for the heavier separated material along the table, said separating partitions terminating short of the forward end of the tablethereby leaving an open space for the expansion of the heavier separated material as it emerges from said passage.

22. A mechanism for separating inter- HID -mixed divided materials including in combination an air pervious table for a bedof creases from the feed end of the table to the discharge'endthereof, and material separating ine'ans comprising separating partitions insets at either side of the table and begin-' ning at the rear and side edges of the table and converging inwardly and forwardly of the table but terminating short of the center thereof, the ends of the successive partitions being farther apart forwardly along the table to provide a forwardly widening passage for the heavier separated material along the table, and means for longitudinally reciprocating the table.

23. A mechanism for separating intermixed divided materials including in combination an air pervious table for a bed of the materials, the table increasing in width from the rear forwardly to 'a median point and thence decreasing in width forwardly, and material separating means comprising separating partitions in sets at either side of the table and converging inwardly and forwardly of the table but terminating short of the center thereof, the ends of the successive partitions being farther apart forwardly along the table to provide a forwardly widening passage for the heavier separated material along the table.

24. A mechanism for separating intermixed divided materials including in combinationan air pervious table for a bed of the materials, the table increasing in width from the rear forwardly to a median point and thence decreasing in width forwardly, and.

material separating means comprising separating partitions insets at either side of the table, disposed substantially parallel to the forward side edges of the table, and converging inwardly and forwardly of the table but terminating short of the center thereof, the ends of the successive partitions being farther apart forwardly along the table to provide a forwardly widening passage for the heavier separated material along the table.

25. A mechanism for separating intermixed divided materials including in combination an air pervious table for a bed of the materials, the table increasing in width from the rear forwardly to a median point and thence decreasing in width forwardly, and material separating means comprising separating partitions in sets at either side of the table, beginning at the rear edges of the table and converging inwardly and forwardly of the table but terminating short of the center thereof, the ends of the successive partitions being farther apart forwardly along the table to 1provide a forwardly widening passage for t e heavier separated material 'along the table.

26. A mechanism for separating intermixed divided materials including in combination an air pervious table for a bed of the materials the pervio'sity of which decreases from the feed end of the table to the discharge end thereof, the table increasing in width from the rear forwardly to a median point and thence decreasing in width forwardly, and material separating means comprising separating partitions in sets at either side of the table, beginning at the rear edges of the table and extending substantially parallel to the forward side edges ofthe table,

from the rear forwardly to a median point and thence decreasing in width forwardly, and material-separating means comprising separatin partitions in sets at either side of the ta lo and converging inwardly and forwardly of the table but terminating short of thecenter thereof, the ends of the successive partitions being farther apart forwardly along the table to provide a forwardly widening passage for the heavier separated material along the table, and means for variably forcing air through the table.

28. A mechanism for separating intermixed divided materials including in combination an air pervious table for a bed of the materials, the table increasing in width from the rear forwardly to a median point and thence decreasing in width forwardly, and material separating means comprising separating partitions in sets at either side of the table, disposed substantially parallel to the forward sideedges of the table, and converging inwardly and forwardly of the table but terminating short of the center thereof, the ends of the successive partitions being farther apart forwardly along the table to provide a'forwardly widening passage for the heavier separated material along the table, and means for variably forcing air through the table.

29. A mechanism for separating intermixed divided materials including in com-, bination an air pervious table for a bed of the materials, the table increasing in width from the rear forwardly to a median point and thence decreasing in width forwardly, and material separating means comprising separating partitions in sets at either side of the table and converging inwardly and forwardly of thetablebut terminating short of the center thereof, the ends of the successive partitions being farther apart forwardly along the table to provide a forwardly widening passage for the heavier separated material along the table, means for variably forcing air-through the table, and means for longitudinally reciprocating the table.

30. A mechanism for separating inter- 5 mixed divided materials including in combination an air pervious table for a bed of the materials the perviosity of which decreases from the feed end of the table to the discharge end thereof, and which also decreases from the center of the table toward the sidesthereof, the table increasing in width from the rear forwardly to a median point and thence decreasing in width forwardly, and material separating means comprisi g separating partitions in setsat either sid of the table, disposed substantially parallel to the forward side edges of the table, andmonverging inwardly and forwardly of the table but terminating short of the center thereof, the ends of the successive partitions being farther apart forwardly along the table to provide a forwardly widening passage for the heavier separated material along the table, means for longitudinally reciprocating the table, and

55 means for re 'ulabl feedin the intermixed 25 y a materials to the table to maintain the bed of materials thereon substantially uniform.

31. A mechanism for separating intermixed divided materials including in combination material separating and progressing means, comprising an air pervious table, means for passing air upwardly through the table, and means for progressing the separated heavier material to the front of the table and means for regulating the discharge of the heavier material from the table, including a support impervious to air, adjacent the point of discharge, and means for supplying air from above to the material on said air impervious support, for aiding the final separation of the lighter and heavier materials.

32. A 'mechanism for separating inter- Ls mixed divided materials including in combination material separating and progressing means, comprising an air pervious table, means for passing air upwardly through the table and means for progressing the sepa- 30 rated heavier material to the front of the table and means for regulating the discharge of the heavier material from the table, including a support impervious to air, adjacent the point of discharge, meansfor supplying air from above and at the sides of the material on the air impervious support, and a pressure controlled discharge gate at the point of discharge. 33. A mechanism for separating inter- 0 mixed divided materials including in combination materials separating and progressing means, comprising an air pervious table increasing in width from the rear forwardly to a median point and thence decreasing in 5 width forwardly, and means for progressing the separated heavier material to the front of the table and means for regulating the discharge of theheavier material from the table, including means for forcing air upon a mass of said heavier material from above and at the sides while on an impervious support, and means for longitudinally reciprocating the table.

. 34. A mechanism for separating intermixed divided materials including in combination material separating and progressing means, comprising an air pervious table and means for progressing the separated heavier material to the front of the table and means for regulating the discharge of the heavier material from the table, including a support impervious to air at the discharge end of the table, means for supplying air from above and at either side of the materials on the air impervious support, for effecting a final separation of the lighter and heavier materials thereon, and a discharge gate, regulated by the pressure of the separated materiels thereagainst, at the point of discharge.

35. A mechanism for separating intermixed divided materials including in combination material separating and progressing means, comprising an air pervious table increasing in width from the rear forwardly to a median point and thence decreasing in width forwardly, and means for progressing the separated heavier material to the 'front of the table and means for regulating the dis charge of the heavier material from the table, including a passageway with an impervious bottom and air pervious sides and top, the passageway being open toward the table and having a pressure regulated gate at its discharge end, and means for longitudinally reciprocating the table.

36. The process of separating intermixed divided materials of different specific gravities, comprising subjecting the materials on a table to the action of upwardly flowing air and vibration, whereby the materials are stratified and progressed along the table, the heavier materials moving along the table into areas gradually increasing in size, while the lighter materials move into areas which at first increase in size and then decrease in size, and so areseparated from the heavier materials. V

37 The process of separating intermixed divided materials of different specific gravities, wherein a bed of intermixed materials on a table is subjected to upwardly flowing air and to vibration, whereby the materials are Stratified and progressed along the table, the heavier materials moving along the table into areas increasing in size toward, the discharge end of the table, while the lighter materials move into areas decreasing in size toward the discharge end of the table, the intensity of the air action being greatest at the feed end of the bed and gradually and progressively decreasing in intensity toward the places of discharge for the lighter and heavier materials.

38. The process of separating intermixed divided materials of different specificgravities which comprises maintaining a bed of said materials of substantial depth on an air pervious table, longitudinally reciprocating the tableand forcing air currents upwardly through the bed to stratify the materials, therebyprogressing a stratum of the material directly forwardly along the table in a central stream to discharge at the forward end thereof, progressing another stratum of the material of different specific gravity laterally forwardly and outwardly from both sides of the central stream to discharge at a plurality of points along the sides of the bed, and gradually and progressively decreasing the intensity of the air currents in the directions of flow of both discharging strata of materials.

39. The process of separating intermixed divided materials varying relatively greatly in size and varying relatively little in specific gravity comprising inantaining a bed of said materals of substantial depth upon an air-pervious table, subjecting the bed of materials to a plurality of forces including fore ing air currents upwardly through the bed and longitudinally reciprocating the table whereby the materials stratify in superposed strata according to their specific gravities, and thereby progressing a stratum of one material along the table to discharge at the forward end thereof and progressing a stratum of another material laterally to discharge along the side of the bed, and gradually and progressively decreasing the intensity of the air currents in the directions of flow of both discharging materials.

40. A mechanism for separating intermixed divided materials varying relatively greatly in size and varying relatively little in their specific gravities including in con bination means for maintaining a bed of the materials of substzmtial depth on an airpervious table, means for stratifying the materials in substantially horizontal superposed strata, means for progressing'the superior stratum of lighter materials to discharge, means for progressing the inferior settled heavier material to discharge .in a direction transverse tothat of the lighter material While maintaining the lighter and heavier strata in their superposed stratified positions, and means for decreasing the perviosity of the table surface both longitudinally and laterally thereof.

41. A mechanism for separating intermixed divided materials which vary relatively very greatly in size and relatively very little in specific gravities which comprises an air pervious table, means forfeeding the intermixed materials near the rear end of the table to maintain a bed of materials thereon undergoing progressive separation, said table having means, comprising a series of intermerging zones of gradually decreasing intensity of air force, for gradating the force of the air action therethrough decreasingly forwardly along the table away from said feeding means'and also transversely from the center of the table outwardly toward the side edges, and means for longitudinally reciprocating the table.

42. The process of separating nnsized intermixed divided materials which comprises feeding the material to a table near one end thereof, and'maintaining a bed of the unsized intermixed materials upon a table provided With separating partitions, reciprocat-- ing the table substantially in the direction of its length and subjecting the bed of material to the floating and separating action of air currents passing upwardly through the table and bed in zones or gradations of intensity, the zones or gradations of greater intensity being nearest the place of feedingon the materials and decreasing progressively in the direction of travel of the material forwardly on the table, and thereby effecting the separation of the intermixed materials in successive stages behind the groups of separating partitions in the various zones or gradations of different air intensities.

43. The process of purifying coal having Wide size variations which comprises maintaining a bed of substantial depth composed of said raw coal, subjecting the bed to loosening and lifting air currents and reciproca tion whereby the bed stratifies, the coal forming a continuous superior, fiotant stratum and the heavier impurities gradually and progressively sinking through the bed in spite of said wide size differences, progressing the fiotant stratum slowly toward a discharge edge and moving the settled impuri ties transversely thereto to discharge, and gradually, progressively and substantially continuously decreasing the lifting and loosening action of the air currents in the direction of flow of the coal stratum and similarly decreasing the air action transversely of the coal flow in the direction of movement of the settled impurities.

44. A mechanism for purifying coal having wide size variations including in combination an air-pervious table having a plurality of substantially parallel separatiiig partitions thereon, means for reciprocating the table transversely of the separating partitions, means for maintaining a bed of said coal on the table, means for passing lifting and loosening air currents through the bed, means for progressing a fiotant stratum of coal across the separating partitions, there being a series of intermerging zones of grad"- ually and progressively decreasing air-intensity on the table in the path of flow of the til) coal stratum, the borders 9f said zonesbeing substantially parallel to the separating partitions and several of said zones each having a plurality of separating partitions therein.

45. A mechanism for separating intermixed divided materials Varying Widely in size but varying relatively little in specific gravity including in combination a longitudinally reciprocable air-pervious deck, a plurality of substantially parallel separating partitions arranged on the deck transversely ,perior fiotant stratum across the separating partitions, and means for discharging settled heavier material guided transversely -by said separating partitions.

46. The process of purifying coal or the like which comprises maintaining a traveling bed of substantial depth containing in intermixture relatively large pieces and fine particles of coal and heavier impurities, vibrating the bed, passing lifting and loosening air currents through the bed to effect a gradual Stratification of the coal and heavier impurities, regulating the air currents to float the fine particles of coal uppermost while larger pieces of coal assume lower and intermediate positions in the upper strata,

a progressing the coal-containing strata to discharge and concurrently effecting a size classification of the coal along the bed by displacing upper, fine particles and the submerged, large pieces of coaliwith respect to each other across the general travel of said strata, delivering the coal in a stream wherein the pieces and particles are gradated in size thereacross, and separately delivering the settled heavy impurities.

47; The process of purifying coal or the like which comprises maintaining a traveling bed of substantial depth containing in intermixture relatively large pieces and fine particles of coal; and heavier impurities, vibrating thebed, passing lifting and'loosening air currents through the bed to effect a gradual stratification of the coal and heavier impurities, regulating the air currents to float and sustain the fine coal particles and the larger coal pieces at different levels in the'upper strata, progressing the coal-containing strata to discharge and concurrently displacing the different size-ranges of coal horizon; tally with, respect to each other to elfect a size gradation of coal across the general travel of said strata, delivering the coal in a stream wherein the pieces and particles are gradated in size thereacross, and separately delivering the settled heavy impurities.

48. The process of purifying coal or the like which comprises maintaining a substantially thick bed containing relatively large pieces and fine particles of intermixed coal and impurities on a vibrating, air-pervious table having a plurality of separating partitions thereon, passing lifting and loosening air currents through the bed, regulating the air currents to float the fine particles of coal uppermost while larger pieces of coal assume lower and intermediate'positions in the up per strata, progressing the bed across the separating partitions, gradually and progressively causing the heavier material to settle through the bed and directing said settled material along the separating partitions, concurrently efi'ecting a substantial size gradation of the coal by displacing the coarse coal pieces for limited distances in the direction of travel of the heavier material, and separately delivering the settled heavier material and the gradated, purified coal. 7

49. The process of purifying coal or the like which comprises maintaining a traveling bed of substantial depth conta-ininginintermixture relatively large pieces and fine particles of coal and heavier impurities, vibrating the bed, passing lifting and loosening air currents through substantially all parts of the bed, regulating the air currents to float the fine particles of coal uppermost while larger pieces of coal assume lower and inter mediate positions in the upper strata, progressing the coal-containing strata to discharge and concurrently classifying the pieces and particles thereof in gradated size relation across the general direction of travel of said strata, progressing settled heavier material beneath the coal-containing strata and transverse to the'general direction of travel of said strata,

and separately delivsung the settled heavy material and the coal. 7 50. The process of purifying coal or the like which comprises maintainin a sloping, traveling bed of substantial epth containing inintermixture relatively large pieces and fine particles of coal and heavier impurities, vibrating the bed, passing lifting and loosening air currents through substantially all parts of the bed, regulating the air currents to float the fine particles of coal uppermost while larger pieces of coalassume lower and intermediate positionsin the upper strata, progressing the coal-containing strata across the slope of the bed to discharge and concurrently classifying the pieces and particles thereof, in substantially gradated size relation across the direction of travel of said strata, progressing settled heavier material beneath the coal containing strataand trans verse to the general direction of travelof said strata, and separately delivering the settled" heavy material and the coal.

51. The process of purifying coal or'the like which comprises maintaining a sloping,

traveling bed of substantial depth containing in intermixture relatively large pieces and fine particles of coal and heavier impurities, vibrating the bed, passing lifting and loosening air currents through substantially all parts of the bed, regulating the air currents to float the fine particles of coal uppermost while larger pieces of coal assume lower and intermediate positions in the upper strata, progressing the coal-containing strata across the slope of the bed to discharge and concurrently classifying the pieces and particles thereof in substantially gradated size relation across the direction of travel of said strata, delivering the coarser coal particles from the upper portion of the sloping bed and delivering the fine coal from a lower portion of said bed, progressing settled heavier material beneath the coal-containing strata and transverse to the general direction of travel of said strata, and separately delivering the settled heavier material.

52. The process of purifying coal or the like which comprises maintaining a sloping, traveling bed of substantial depth containing in intermixture relatively large pieces and fine particles of coal and heavier impurities, vibrating the bed, passing lifting and loosening air currents through substantially all parts of the bed, regulating the air currents to float the fine particles of coal uppermost while larger pieces of coal assume lower and intermediate positions in the upper strata, progressing the coal-containing strata across the slope of the bed to discharge, delivering the finer coal particles from a lower portion of the bed and the coarser coal pieces from an upper portion thereof, progressing settled heavier material beneath the coal containing strata and upwardly along the sloping bed, and delivering said settled heavier material separately from the coal.

53. The process of purifying coal or the llke which comprises maintaining a travelmg bed of substantial depth containing in intermixture relatively large pieces and fine particles of coal and heavier impurities, vi brating the bed, passing lifting and loosen mg alr currents through substantially all parts of the bed, regulating the air currents to float the fine particles of coal uppermost whlle larger pieces of coal assume lower and lntermediate positions in the upper strata, progressing the coal-containing strata to discharge, progressing settled heavier material beneath the coal-containing strata and trans- Verse to the general direction of travel of said strata, progressing settled heavier impurities beneath the'coal-containing strata and transverse to the general direction of travel of said strata discharging the settled impurities from the bed, delivering the coarser pieces of coal adjacent the discharge locus of the impurities and delivering the finer coalparticles at loci relatively'remote therefrom. 54. The process of purifying coal or the 'permost and to strati like which comprises maintaining a forwardly-narrowing bed of substantial depth containing in intermixture relatively large pieces and fine particles of coal and heavier impurities, vibrating the bed, passing lifting and loosening air currents through subs antially all parts of the bed, regulating the air currents to float the fine particles of coal uppermost while larger pieces of coal assume lower and intermediate positions in the upper strata, progressing the coal-containing strata generally forwardly along the bed to discharge, guiding and deflecting settled heavier material transversely beneath the flotant coal containing strata, delivering the finer coal particles from a longitudinally median portion of the bed' and delivering the coarser coal pieces near the front end of the bed, and separately delivering the settled heavier material.

55. The process of purifying coal or the like which comprises maintaining a traveling bed of substantial depth containing in intermixture relatively large pieces and fine particles of coal and heavier impurities, vibrating the bed, passing lifting and loosening air currents through substantially all parts of the bed, regulating the air currents to float the fine particles of coal uppermost while larger pieces of coal assume lower and intermediate positions in the upper strata, progressing the coal-containing strata to d1s- .charge and concurrently classifying the pieces and particles thereof in gradated size relation across the general direction of travel of said strata, gradating the intensity of the air currents in the path of travel of the coal-containing strata, progressing settled heavier material beneath the coalcontaining strata and transverse to the general direction of travel of said strata, and separately delivering the settled heavy ma terial and the coal.

56. A mechanism for separating intermixed divided materials including in combination a longitudinally reciprocable, air pervious table, means for maintaining there on a substantially thick bed of intermixed coal and impurities containing pieces and particles varying relatively greatly in size, means for passing lifting and loosening air currents through the table, said currents being regulated to float the finest coal up- 7 the larger coal pieces lower in the bed, a plurality of separating partitions disposed forwardly and transversely of the direction of reciprocation, a forwardly and transversely'disposed spillage edge for the lighter material, means for progressing flotant, coal-containing strata forwardly and across said separating partitions, means beyond the ends of the separating partitions for discharging settled heavier material, means for arranging the pieces and particles of coal in a sub tantial size grada- 

